This invention relates to an electronic switch in a telephone system and, in-particular, to an electronic switch which provides call routing and connection to service node/intelligent peripherals.
Electronic switches are in use today which enable subscribers to be routed to so called xe2x80x9cservice node/intelligent peripheralsxe2x80x9d (referred to hereinafter as xe2x80x9cSN/IPsxe2x80x9d or xe2x80x9cIPsxe2x80x9d). Typically, a SN/IP is a facility in the telephone system which can be called by a subscriber for some specified service. These facilities are usually provided with some degree of intelligence so that the subscriber and SN/IP can communicate in an interactive fashion. Examples of SN/IPs in use today are the voice mail service nodes now being offered by telephone companies to subscribers for voice mail services.
In present telephone systems which employ SN/IPs, for a subscriber to gain access to a SN/IP, the subscriber must first dial an access code or number. This dialed access code is then analyzed like a normal call by the call routing digit receiver and analyzer functionality of the switch. Once the digits are analyzed and the SN/IP identified, the call is routed by the switch to the SK/IP over an appropriate communication path. After connection to the SN/IP, to place another call the subscriber must first hang up, i.e., go on-hook, to cause the switch to terminate the communication path with the SN/IP.
Also, when connected to a SN/IP, all existing systems require that any digit transmission be dual tone multiple frequency (DTMF) transmission.
The latter requirement prevents subscribers with dial pulse transmissions, i.e., rotary dialing equipment, from being able to use the SN/IP facilities. Also, the need to initially dial an access code to reach a SN/IP and to have to terminate or hang-up in order to be able to dial a further call when connected to a SN/IP present drawbacks with respect to time, effort and demands placed on the subscriber.
It is, therefore, an object of the present invention to provide an electronic switch and SN/IP in a telephone system which have been improved to avoid the aforesaid-drawbacks.
It is a further object of the present to provide the aforesaid improved switch and SN/IP, while preserving other normal and usual electronic switch functions.
In accordance with a first aspect of the present invention, the above and other objectives are in part realized in an electronic switch which is adapted to provide routing and connection of a subscriber to a SN/IP in response to an off-hook status for the subscriber. The electronic switch is further adapted to be able to receive and analyze dialed digits from the off-hook subscriber for further call routing and connection both when the aforesaid connection to the SN/IP is being established and during its maintenance. To this end, the switch is additionally adapted, upon receipt of dialed digits from the subscriber, to terminate the connection process with respect to the SN/IP and to process the received digits via its digit analyzer functionality in the normal manner.
With the electronic switch of the invention so adapted, a subscriber going off-hook is automatically connected with an associated SN/IP and the subscriber can interact with the SNJ,IP immediately and without any need to dial. Furthermore, since dialed digits from the subscriber can still be received and processed by the digit analyzer functionality of the switch and since connection to the SN/IP is dropped upon dialed digits being received, the subscriber is free to make a call at any time without having to hang-up.
In the embodiment of the invention to be disclosed hereinafter, the electronic switch includes an off-hook status functionality for detecting off-hook status of a subscriber, a routing digit receiver and analyzer functionality for receiving and analyzing dialed digits, a routing and connection functionality for routing and connecting calls and a control functionality for effecting overall control of the other functionalities.
In a further aspect of the invention, the electronic switch of the invention is additionally adapted to provide call routing and connection of a subscriber to a SN/IP through conventional access code dialing and conventional routing, but with the added functionality of dial pulse to DTMF conversion for digits transmitted over the established communication path. In this way, coded access to a SN/IP over a stable communication path (i.e., one established by dialed digits) can be effected for subscribers with dial pulse dialing.
In yet a further aspect of the present invention, the SN/IP is adapted to perform dialing functions and to invoke call features (transfer, etc.) for a subscriber connected to the SN/IP (either through off-hook status or access code dialing) upon the request of the subscriber and the electronic switch functionality is further adapted to process these dialing functions and call features as if made by the subscriber, including billing of requested calls to the associated subscriber.